Apparatus for sensing the disposition of knit material



Aug. 8, 1967 R. L. KOSROW 3,334,729

APPARATUS FOR SENSING TEE DISPOSITION OF KNIT MATERIAL Filed Oct. 22, 1965 5 Sheets-Sheet 1 ATTORNEYS Aug. 8, 1967 R. KOSROW 3,334,729

APPARATUS FOR SENSING THE DISPOSITION OF KNIT MATERIAL Filed Oct. 22, 1965 3 Sheets-Sheet 2 v DELAY DEL I F INVENTOR ROB ERT L. KOSROW ATTOR N EYS R. L. KOS ROW Aug. 8, 1967 APPARATUS FOR SENSING THE DISPOSITION OF KNIT MATERIAL 3 Sheets-Sheet 3 Filed Oct. 22, 1965 5 R Y mw WM N0 R WR M N u K 9' L m E w 1 R "W M United States Patent O APPARATUS FOR SENSING THE DISPOSITION OF KNIT MATERIAL Robert L. Kosrow, Elk Grove Village, 11]., assignor to Union Special Machine Company, Chicago, lll., a corporation of Illinois Filed Oct. 22, 1965, Ser. No. 501,262 12 Claims. (Cl. 198232) This invention relates to apparatus for detecting the failure of a section of material to conform to a predetermined path of travel while being advanced by a conveyor means and more specifically, to a means for sensing and indicating the incorrect disposition of knit goods on a moving conveyor of a work handling or sewing unit, and thereupon inhibiting the operation of the conveyor and/ or the unit so as to permit the operator to correct the disposition of the faulty knit goods.

In the fabrication of fabrics, many operations are performed at various Work stations and in an assembly line basis. In many instances, the fabric is transported to a work station or between work stations by conveyors. In many applications, a work station, such as a sewing machine, is positoined along an edge of the conveyor so that the conveyor must transport the fabric in alignment with the sewing machine.

Also, it is necessary that the fabric be oriented in a predetermined manner as the fabric or materail approaches the particular work station. For example, many fabrics have an inner side and an outer side and one or the other of the sides must be face up while being manipulated, for example, being advanced by a conveyor to asewing machine.

In the case of a cut piece or section of knit goods material, the material has a tendency to curl along certain of its edges toward one of its sides. This side will be called the right side. It is this tendency of the material to always curl in one direction or roll toward one side that the present invention utilizes in the sensing apparatus set forth which makes certain that the material blanks being fed to a work station are being advanced with the proper side up. This is especially important when work is being fed into an automatic sewing unit where improper feeding of the work piece would result in rejected sewed blanks and the resultant unnecessary loss of time and material.

Accordingly, it becomes desirable to provide a means for sensing for the orientation or curl of knit goods and the present specification is directed toward that goal. Although it is not necessary that the material curl in order to be sensed and detected according to the teachings of the present invention, the curl of knit sections severed from a larger piece of goods are particularly suitable for use in the practice of the invention.

Accordingly, it is the principal object of the present invention to improve conveyor means for advancing work pieces by detecting any work pieces having portions which may overhang the conveyor means.

It is a further object of the present invention to improve work piece advancing means by detecting the non-conformity of the work piece to a predetermined path of travel toward a work station.

It is a further object of the present invention to provide an apparatus for detecting the position of an advancing work piece failing to conform to a predetermined path of travel toward a work station.

It is a further object of the present invention to provide an apparatus for detecting the presence of a work piece, advancing along a conveyor to a work station, having a portion of the work piece which overhangs the conveyor edge.

It is a still further object of the present invention to provide an apparatus for detecting the presence of a work piece advancing along a conveyor to a work station which does not have a portion of the work piece overhanging the conveyor edge.

These and other objects of the present invention are accomplished by providing a source of motor power which drives a conveyor through a clutch. The source of motor power may also serve to operate a Work station, such as a sewing machine, positioned adjacent and along an edge of the conveyor.

There are at least two dilferent required positions of a work piece being advanced to a work station along the conveyor; in a first instance, it may be desirable that the work piece curl upwardly and not overhang the conveyor. In this situation, photoelectric detecting circuitry positioned adjacent the edge of the conveyor would sense for and indicate the presence of any work pieces having portions overhanging the edge of the conveyor. No indication would be forthcoming in the event that the work piece was properly positioned upon the conveyor with its curled edge or edges turning upwardly. In the second instance, it may be the proper position for the work piece to have a portion curled over the edge of the conveyor. Accordingly, the photoelectric sensing means would now sense for this condition and sound an alarm and stop the apparatus in the event that no overhanging material is detected. A delay means is included in the control circuitry which has a delay period equal to the time ofpassage between successive work pieces so that the short exposure of the photocell to the source of illumination during the interval between successive work pieces would not indicate the absence of an overhanging portion of the work piece.

The invention both as to its organization and method of operation together with further objects and advantages thereof will best be understood by reference to the following specification taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a perspective view of a major portion of the apparatus and illustrating a work piece being advanced along conveying means to a work station;

FIGURE 2 is a schematic diagram, partly in block form, and showing the electrical control circuitry incorporated for detecting an overhanging edge of material;

FIGURE 3 is an elevational view and illustrating the relative positions of the photoelectric detector, the source of illumination, the conveyor, and an advancing work piece, the work piece being in position so as to not intercept the light path;

FIGURE 4 is a view similar to the FIGURE 3 but illustrating the interception of the light path to the photocell by a work piece overhanging an edge of the conveying means;

FIGURE 5 is a sectional 'view taken along the line 5-5 of the FIGURE 1 and showing two possible positions of a work piece in relation to the overhanging detecting means;

FIGURE 6 is a sectional view taken along the line 6-6 of the FIGURE 5 and is the view looking upwardly from under the conveyor toward a work piece being advanced by the conveyor;

FIGURES 7 and 8 illustrate alternate mounting means for the source of illumination and photoelectric detector, respectively; and

FIGURE 9 is an elevational view showing the positions of the alternate mounting means of the FIGURES 7 and 8 as incorporated into the system.

With reference to the FIGURE 1, the work station and material conveying unit is illustrated along with the apparatus for detecting the overhang of material along the material conveying unit. More specifically, a pair of shafts 12 and 14 are suitably supported upon a base member 16 and have a plurality of webs 18 spaced from each other and about the shafts 12 and 14. The webs 18 form the material supporting portion and when the shaft 14 is rotated -by any suitable means to be hereinafter described, a work piece 20 supported upon the webs 18, will be advanced toward a work station 22, such as a sewing ma chine or sewing station. It will be assumed that the shaft 14 will be rotated in the direction to permit the advancement of the work piece of knit or relatively limp material 20 toward the work station 22 and not in the opposite direction.

As shown in the FIGURE 1, a motor and clutch unit 24, commonly referred to as a transmitter, is provided for driving a sewing machine 26 at the work station 22 and also for driving the conveyor. A belt 28 is driven by the motor and clutch unit 24 and rotates a pulley 30 connected to the work station 22. The pulley 30 rotates a shaft 32 and through the cooperation of a plurality of pulleys, belts, and a speed reducer generally indicated at 34, a shaft 36 coupled to the shaft 14 advances the webs 18 of the conveyor.

The motor and clutch unit 24 is mounted beneath the base member 16 and may be suitably suspended from the undersurface of the base member 16 by suitable brackets. A lever 38 controls the engagement of the clutch unit of the motor and clutch unit 24. At one of its ends, the lever 38 is formed with an upwardly extending arm engaging the axially shiftable clutch element. At its opposite end, the lever 38 is connected to the upper end of an extensible rod 40. The lower end of the rod 40 is connected to the magnet of a solenoid 42 fixedly mounted on a transversely extending shaft 44 of the leg assembly of the unit. The lever 38 is urged clockwise by a pivot pin 46 into a clutch disengaging position by a torsion spring 48.

Upon energization of the solenoid 42, the lever 38 will be angularly displaced about the pivot pin 46 in a counterclockwise direction, thereby engaging the clutch element of the transmitter 24. Together with the clutch element, a pulley 50 will be rotated. The pulley 50 is connected by the belt 28 with the combined hand wheel and pulley 30 secured to the drive shaft of the sewing machine 26 at the work station 22. If the solenoid 42 is deenergized, the lever 38 will be released and the clutch again disengaged. The driven shaft of the clutch unit will be quickly stopped by the brake means incorporated in the motor and clutch unit 24.

The solenoid 42 controlling the motor and clutch unit 24 of the FIGURE 1 is controlled by the output of a photoelectric cell 52 mounted adjacent a belt support platform 54 and upstream from the sewing machine 26. A mounting bracket 56 for the photocell 52 is secured to the base member 16. The mounting bracket 56 has an upright member formed with a vertical slot 58. The threaded end of a shoulder stud 60 is received in the slot 58 of the mounting bracket 56. A nut 62 tightened on the threaded end of the shoulder stud 60 against the mounting bracket 56 serves to retain the shoulder stud 60 in place. A bore 64 of a suitable size is formed through the shoulder portion of the stud 60 in perpendicular relation to the axis of the stud 60. The bore 64 is intercepted by a threaded axial bore in the flat end of the stud 60 in which is received a screw 66 best shown in the FIG- URE 5.

With reference now to the FIGUREv 5, the photo- 7 electric cell 52 is received in the bore 64 and retained therein by the screw 66. The photocell 52 may be adjusted in vertical or angular direction by manipulation of the nut 62, best shown in the FIGURE 1. The photocell 52 is part of a detecting or sensing arrangement including a light source 68 mounted beneath the belt support arm 54 across from the photocell 52 so as to direct its illumination to the photocell 52. The light source 68 is mounted in a similar manner as the photocell 52 but on a bracket 70 depending from the undersurface of the belt support platform 54. The bracket 70 has a vertical slot 72 which permits the positioning of the light source 68 by manipulation of a screw 74 and a nut, not shown, which couple the light source 68 to the bracket 70, as shown. The bracket 70 is secured to the undersurface of the belt supported platform 54 by any suitable means such as a screw 76. The work piece 20 will be observed in the FIGURE 5 having an extending edge or overhanging portion 78 where in the position shown, the edge 78 would not interrupt the illumination path between the light source 68 and the photoelectric cell 52. In dotted outline, the extending edge or overhanging portion is shown as 78 wherein interruption of the light path would occur.

The FIGURES 3 and 4 clearly illustrate the positions of the illumination path from the light source 68 directed toward the photoelectric cell 52. In addition, the adjustability of the light source 68 and the photoelectric cell 52 are clearly visible in that these elements may be moved upwardly or downwardly in their respective vertical slots of their supporting brackets. Further, the rotational motion about the axis of their supporting studs is also visible. In the FIGURE 3, the extending edge 78 of the work piece 20 is upward so that the light path is not interrupted. In the event that this mode of operation is desired, the forward motion of the conveyor and the joining action of the sewing machine 26 would continue. If, however, the mode of operation was that the extending edge 78 should overlap the edge of the belt support platform 54, then the illumination from the light source 68 to the photoelectric cell 52 would halt the foregoing operations at the conclusion of the delay period controlled by a delay means to be described with subsequent reference to the FIGURE 2. 1

In the FIGURE 4, the depending edge 78 of the work piece 20 is shown in its position interrupting the light path from the light source 68 to the photoelectric cell 52 and if this criterion has been previously established, continuation of the action by the conveyor and the sewing machine 26 would continue. If, however, the overhanging edge 78 of the work piece 20 should be in the position shown in the FIGURE 3, then the output from the photoelectric cell 52 would serve to inhibit the further advancement of'the conveyor and stop the sewing machine 26.

With reference to the FIGURE 2, the major portion of the control circuitry is shown. If it is desired that the work piece 20 be advanced with its correct side up to the sewing machine 26, then the natural curl along the longitudinal edges of a knit goods ply will be on the upper side thereof. As the ply or work piece 20 is fed along the edges of the belt support platform 54, the curl will not overlap or overhang from the edge. However, the curl will overlap the edge if the knit goods ply or work piece 20 is deposited with the correct side down upon the conveyor webs 18. The curl will then roll over the edge of the belt support platform 54 and its extreme edge will depend somewhat beyond and below the undersurf-ace of the support platform 54. The photocell 52 and the light source 68 may be so adjusted that the over-rolling curl will cut through the light path so as to vary the current in the photoelectric cell 52. This positional adjustment will have to be made to suit the curling tendency of the particular work piece 20.

If the work piece 20 is to be fed to the sewing machine 26 with its correct side upwardly, then the amplifier and control unit 80 of the FIGURE 2 will be so adjusted that a current is supplied to a relay coil 82 of a relay 84 when the photocell 52 is darkened. That is to say, when an uninterrupted light path exists between the photoelectric cell 52 and the light source 68, no current will be supplied to the relay coil 82 so as to open the circuit through the solenoid 42'.

The amplifier and control unit 80 is coupled to a suitable source of power via the conductors from a plug 86. The outputs from the photoelectric cell 52 and the light source 68 are directed to the amplifier and control unit 80 via the conductors 88 and 90, respectively. The amplifier and control unit '80 will amplify the output from the photoelectric cell 52 so as to provide a suitable magnitude of power to energize the relay coil 82 of the relay 84, the relay 84 also including a pair of stationary contacts 92 and 94 and a movable contact 96. The relay coil 82 controls whether the movable contact 96 is in engagement with the stationary contact 92 or the stationary contact 94. In the position shown, the relay coil is not energized and the normal position of the movable contact 96 is that shown, i.e., in engagement with the stationary contact 92. A suitable source of power is applied to a plug 98 and When a series switch 100 is closed, the current path exists through the switch 100, the movable contact 96, the stationary contact 92, through a conductor 102 and through the solenoid coil 42 of the solenoid 42 and then to ground.

When the work pieces 20 are being advanced by the webs 18 of the conveyor with the correct side up, then the light path between the photoelectric cell 52 and the source of illumination 68 is uninterrupted. Under these conditions, the relay coil 82 is not conducting and the position of the elements of the relay 84 is that shown in the FIGURE 2. If, however, a work piece 20 is incorrectly fed and its depending or extending overhanging edge 78 interrupts the light path between the photoelectric cell 52 and the light source 68, then the amplifier and control unit 80 will supply current to the relay coil 82 thus causing the movable contact 96 to disengage the stationary contact 92 and engage the stationary contact 94. As a result, current is no longer supplied via the conductor 102 to the solenoid coil 42' so that the motor and clutch unit 24 of FIGURE 1 is disengaged thereby stopping the conveyor and the sewing machine 26. With the movable contact 96 in engagement with the stationary contact 94, an indicator light 104 will be energized so that an observer can readily detect that the apparatus has been stopped.

In its other mode of operation wherein the material is fed with its correct side downwardly and the light path between the light source 68 and the photoelectric cell 52 should be interrupted except for the brief period between successive work pieces, additional controls are provided in the amplifier and control unit such as an inverter having an OFF and an ON position since current in the photoelectric cell 52 will now be employed in the amplifier and control unit to energize the relay 84. In addition, a delay is included having an OFF and an ON position so as to compensate for the deenergization of the photoelectric'cell 52 between the trailing edge of one work piece and the leading edge of the next successive Work piece. The amount of the delay may be set by a delay interval having a plurality of contacts which in the first mode would be set at zero and in the present mode under discussion, at a position to correspond with the usual time of passage between successive work pieces.

In the present mode under discussion wherein low or no current should flow in the photoelectric cell 52 since the depending edge or overhanging portion 78 of the work pieces 20 should interrupt the light path, current will not flow in the relay coil 82 until the photoelectric cell 52 has been energized from the light source 68 a period of time exceeding the time delay of the delay circuit in the amplifier and control unit 80. At the expiration of this time period, it must be assumed that either a subsequent work piece is not available or the subsequent work piece has been fed with the correct side up so that the logic now requires that the conveyor and work station 22 be inhibited. At the expiration of this delay, and if current continues to flow in the photoelectric cell 52, the relay coil 82 is energized thus causing the movable contact 96 to disengage the stationary contact 92 and engage the stationary contact 94 thereby breaking the circuit through the solenoid coil 42' of the solenoid 42 and cansing the motor and clutch unit 24 to disengage so as to stop the conveyor and the sewing machine 26. Thereupon,

the indicator light 104 will be illuminated to so indicate the condition.

The FIGURE 6 is a sectional view taken along the line 6-6 of the FIGURE 5 and looking upwardly so as to expose the extending edge 78 of the work piece 20. If the edge 78 extends downwardly a suflicient distance, then the light path from the light source 68 to the photoelectric cell 52 will be interrupted and the control circuitry 80 of the FIGURE 2 will be actuated. The figure ill-usttrates that shoulder stud 106, similar to the shoulder stud 60, supports the light source 68 which is held in position by the screw 74. A nut 108 secures the shoulder stud 106 to the bracket 70. A screw 76 couples the bracket 70 to the underside or undersurface of the belt support platform 54.

The FIGURE 7 is a perspective view of the light source coupling arrangement and clearly illustrating the adjustable features of the shoulder stud 106 within the slot 72 as controlled by the nut 108 and the movement permitted by the light source 68 within the shoulder stud 106 by manipulation of the screw 74.

The FIGURES 8 and 9 illustrate various other ways for mounting the photoelectric cell 52 and the light source 68. For example, in the FIGURE 8 the light source 68 may be secured to a flat plate 112 having a slot 114 formed therein for coupling the plate 112 to an angle bracket 116 with adjustment being permitted within the vertical slot 114 by a screw 118. A clamp 120 surrounds the case of the light source 68 and secures the light source 68 to the plate 112.

In the FIGURE 9, the light source 68 is secured to the bracket 116 connected to the plate 112 and the clamp 120 has a setscrew 122 for securing the light source 68 thereto. The photoelectric cell 52 is secured to a vertical bracket 124 having an aperture therethrough and when a pair of nuts 126 and 128 are tightened thereagainst, the photoelectric source 52 is secured in place. The vertical bracket 124 abuts a bracket 130 and is secured thereto by a screw 132. By the arrangement shown in the FIGURE 9, an alternative arrangement is aitorded to that shown in the FIGURE 5 for securing the photocell 52 and the light source 68 in place. If the extending edge 78' of a work piece 20 assumes the position shown in dotted outline, then the light path between the light source 68 and the photoelectric cell 52 will be interrupted thus actuating the amplifier and control unit 80 of the FIGURE 2 as hereinbefore described.

Thus, there has been described and illustrated a method and apparatus for detecting Whether the edge of a Work piece overhangs a conveying apparatus as the work piece is being advanced to a Work station. The control circuitry operates in two difl'erent modes. In the first mode, if it is desired that the curled edge of the work piece extends upwardly, then in the event that the curled edge extends downwardly, a photoelectric cell will be actuated so as to inhibit the operation of the conveying means and the operation of the means at the work station. In the second mode, if it is desired that the curled edge extends downwardly, the photoelectric cell adjacent the downward edge will remain inactive until the expiration of a time delay circuit indicating that the curled edge has not been posi-v tioned between the light source of the photoelectric cell for the predetermined length of time. Accordingly, the control circuitry will inhibit the operation of the conveying means and the apparatus at the work station.

It will be readily understood that the present invention may be embodied in other specific forms without departing from the spirit and the essential characteristics of the invention. The present embodiment is, therefore, to be considered in all respects as illustrative and the scope of the invention being indicated by the appended claims rather than the foregoing description, and all changes which come Within the meaning and range of the equivalency of the claims are, therefore,.intended to be embraced therein.

What is claimed is:

1. Apparatus for detecting a Work piece of knit material having a natural curl and failing to conform to a preselected orientation regarding its faces during its travel along a predetermined path, said apparatus comprising means for advancing a succession of work pieces having portions overhanging said means for advancing, means adjacent said means for advancing for detecting the disposition resultant from said natural curl of said overhanging portions in relation to said means for advancing, logic means for determining whether the disposition of said overhanging portions conforms to an established criterion, and means coupled to said logic means and communicating with said means for advancing for permitting transmission of control signals thereover in the event the overhanging portion fails to conform to the established criterion.

2. The apparatus as defined in claim 1 wherein said means for detecting the disposition of overhanging portions is a photoelectric cell energized from a source of illumination.

3. The apparatus as defined in claim 1 wherein said logic means includes means for selecting a first criterion wherein conformity to the criterion infers no work pieces having downwardly overhanging portions.

4. The apparatus as defined in claim 1 wherein said logic means includes means for selecting a second criterion wherein conformity to the criterion infers work pieces having downwardly overhanging portions.

5. The apparatus as defined in claim 4 including means in said logic means for inhibiting said means for detecting during the interval between the passage of the trailing edge of a piece and the leading edge of the next piece.

6. Apparatus for detecting a work piece of relatively limp naturally curled material failing to conform to a preselected orientation regarding its faces during its travel along a predetermined path, said apparatus comprising a conveyor for advancing a succession of work pieces in spaced relation, means for controlling said conveyor, photoelectric means adjacent said conveyor for detecting the disposition of overhanging portions of Work pieces resultant from the natural curl of the material, control means coupled to said photoelectric means and responsive thereto for generating an inhibit signal upon receipt of an indication from said photoelectric means of an improper disposition of an overhanging portion, and means for applying said inhibit signal to said means for controlling to thereby halt said conveyor.

7. The apparatus as defined in claim 6 wherein said control means includes a relay having contacts for controlling a solenoid for actuating said means for controlling said conveyor.

8. Apparatus for detecting the disposition of overhanging portions of work pieces of relatively limp material having a natural curl, the disposition of the overhanging portion being determined by said curl, said apparatus comprising means for advancing a succession of work pieces along a predetermined path, means for detecting said disposition of said overhanging portion as determined by said natural curl, means responsive to said detecting means for determining an improper disposition of an overhanging portion.

9. Apparatus as defined in claim 8 further including means for controlling said conveyor, control means including delay means having a preselected delay period corresponding to the time separation between successive work pieces, said control means being coupled to said detecting means and responsive thereto for generating an inhibit signal at the expiration of said delay period upon receipt of an indication from said photoelectric means of an improper disposition of an overhanging por- 8 tion, and means for applying said inhibit signal to said means for controlling to thereby halt said conveyor.

10. The apparatus as defined in claim 8 wherein said control means further includes a relay having contacts for controlling a solenoid for actuating said means for controlling said conveyor.

11. Apparatus for detecting a work piece of knit material having a natural curl and failing to conform to a preselected orientation regarding its faces during its travel along a predetermined path comprising a conveyor for continuously advancing a succession of work pieces in spaced relation, clutch means for controlling said conveyor, a first adjustable bracket means positioned below and along an edge of said conveyor, a source of illumination secured to said first adjustable bracket means, a second adjustable bracket means supported and in spatial relation to said first adjustable bracket means, photoelectric means secured to said second adjustable bracket means and aligned with said source of illumination, said source of illumination and said photoelectric means cooperating to detect the disposition resultant from said natural curl of portions of work pieces overhanging said conveyor, control means coupled to said photoelectric means and responsive thereto for generating an inhibit signal upon receipt of an indication from said photoelectric means of an improper disposition of an overhanging portion arid means for applying said inhibit signal to said clutch means for disengaging said clutch means and thereby halt said conveyor, said control means including a relay having contacts for controlling the current to a solenoid, said solenoid coupled to control said clutch means.

12. Apparatus for detecting a work piece of knit material having a natural curl and failing to conform to a preselected orientation regarding its faces during its travel along a predetermined path comprising a conveyor for continuously advancing a succession of work pieces in spaced relation, clutch means for controlling said conveyor, a first adjustable bracket means positioned below and along an edge of said conveyor, a source of illumination secured to said first adjustable bracket means, a second adjustable bracket means supported and in spatial relation to said first adjustable bracket means, photoelectric means secured to said second adjustable bracket means and aligned with said source of illumination, said source of illumination and said photoelectric means cooperating to detect the disposition resultant from said natural curl of portions of work pieces overhanging said conveyor, control means including delay means having a predetermined delay period corresponding to the time separation between successive work pieces, coupled to said photoelectric means and responsive thereto for generating an inhibit signal at the expiration of said delay period upon receipt of an indication from said photoelectric means of an improper disposition of an overhanging portion, means for applying said inhibit signal to said clutch means to thereby halt said conveyor, said control means including a relay having contacts for controlling the current to a solenoid, said solenoid coupled to control said clutch means.

References Cited UNITED STATES PATENTS 1,864,808 2/1932 Hohn 250-223 X 1,977,732 10/1934 Mattler 198-232 X 2,323,351 7/1943 Pechy 198-232 X 2,636,603 4/ 1953 Feick 209-111] 2,900,934 8/ 1959 Judelson 112-63 2,902,151 9/1959 Miles 209111.7

EVON C. BLUNK, Primary Examiner. WARD A- SRQKA; Extlmincr. 

1. APPARATUS FOR DETECTING A WORK PICE OF KNIT MATERIAL HAVING A NATURAL CURL AND FAILING TO CONFORM TO A PRESELECTED ORIENTATION REGARDING ITS FACES DURING ITS TRAVEL ALONG A PREDETERMINED PATH, SAID APPARATUS COMPRISING MEANS FOR ADVANCING A SUCESSION OF ORK PIECES HAVING PORTIONS OVERHANGING SAID MEANS FOR ADVANCING, MEANS ADJACENT SAID MEANS FOR ADVANCING FOR DETECTING THE DISPOSITION RESULTANT FROM SAID NATURAL CURL OF SAID OVERHANGING PORTIONS IN RELATION TO SAID MEANS FOR ADVANCING, LOGIC MEANS FOR DETERMINING WHETHER THE DISPOSITION OF SAID OVERHANGING PORTIONS CONFORMS TO AN ESTABLISHED CRITERION, AND MEANS COUPLED TO SAID LOGIC MEANS AND COMMUNICATING WITH SAID MEANS FOR ADVANCING FOR PERMITTING TRANSMISSION OF CONTROL SIGNALS THEREOVER IN THE EVENT THE OVERHANGING PORTION FAILS TO CONFORM TO THE ESTABLISHED CRITERION. 